Experiments With Girls
by Plesiosaur
Summary: Bubbline Real World challenge fic. An accident in the lab turns an experiment in neuroscience from Nobel Prize winning to straight up Twilight Zone. Bonnie might have accidentally broken the laws of physics and Marceline is not impressed. Without any way of reversing the effects they're pretty much stuck until they can figure out how to fix things. *Warnings for smut and sex*
1. Chapter 1

**I am apparently snowed in with requests! It's really awesome! Thanks guys! I love doing requests and challenge fics because I end up writing stuff I'd never have thought about on my own. The wonderful Schwarzeil requested a body-swap real world Bubbline AU, so pretty much completely different in every possible way from the last fic I wrote. This is also gonna be at least two chapters because I just couldn't do everything I wanted with it in one. So here is the first chapter.** **I solemly swear that I'll update 40 Weeks tomorrow night too, promise. I've just been stuck with a particularly tricky scene. But tomorrow, I give you my word.**

 **Serious talk; there's some stuff in here that isn't terribly graphic but does imply at least a level of creepiness and mild sexual assault. So if that's triggering for you then I really suggest you don't read it, even knowing that retribution is pretty much instant in this case. Just, I'd hate to think anyone was triggered by reading something they weren't expecting, cause PTSD and stuff isn't a joke.**

 **Content Warning: boobs, piercings, nudity, feels, unwelcome touching, injury, implied kinkiness, borderline partner abuse. This turned out more serious than I'd intended.**

* * *

"I'm only doing this because I need to eat."

"Yeah, you said. Now be quiet and let me set up the equipment."

Marceline fell silent but she couldn't resist rolling her eyes, just a little. She wasn't strapped down but there were connection points on the chair, it looked decidedly kinky. Man science was weird.

"Do we have a safe word?" she asked after a few moments of silence.

"Ha ha. Yeah, your safe word is 'thanks for working it so I can be part of the paid experiment, so I don't have to sell all my stuff on Ebay again to afford food this month because I suck at money management and being an adult in any form'. Think you can remember that?"

"I'll paraphrase. If it gets too kinky I'll just say 'Bonnie's a smug butthole' and you'll know I need untying."

"Marceline, please. I need this experiment for my thesis. If I can prove that our brain patterns can influence each other through direct electrical connection-"

"Yeah you win some kinda fancy science award, I know. Do they have a 'Best Lab Rat' category? Cause I'd be an odds-on favourite to win that."

Bonnie just sighed and shook her head, still staring at the screen of the large and very sci-fi looking machine she had her friend hooked up to. Marcy tried to catch her eye and grin but the redhead was determinedly looking at her work and ignoring her. Marceline couldn't even have begun to explain what transcranial neurobiological signal transduction actually was but it involved her and Bonnie both being hooked up to a big machine and trying to guess what each other were thinking. It sounded pretty stupid and pointless but Marcy was getting paid for it and she'd blown most of that semester's student loan on tickets to a festival so she was grateful for the money even if it wasn't a huge amount. Whatever, when she was old and wrinkled she'd remember rocking out for an entire weekend much more vividly than what she'd eaten anyway.

"Right, we're nearly ready. We'll start with me and see if you can guess the objects I'm imagining. I'll run through a series of surreal objects, I won't tell you what they are. Just try to picture them too and see if you can pick up any idea of what those things are. Is that simple enough?" Bonnie asked after several long minutes of silence.

"Oh yeah, simple enough even for my feeble little musician brain to understand. You clever science woman, me stupid music woman. Duhrrrr."

"Remind me again why we're even friends?"

"You wanted someone with a car to move your stuff at the end of your first year and Finn helpfully volunteered me without asking first. It's entirely your dumb boyfriend's fault."

"Finn isn't my boyfriend, he isn't dumb and I bought you takeout and paid for your petrol so don't whine about me asking to borrow your car, you could have said no." Bonnie replied with a frown. "Now shut up, we've gotta start. I only have half an hour booked with this machine and it's taken like, half that time just to prepare." Bonnie sighed, exasperated.

"Anyone ever tell you that you're super bossy?"

"Nope. But I've been told I have good leadership skills so maybe you just have a problem with authority."

"Yeah right. I think the object you're thinking of right now is a pair of handcuffs and a spanking paddle, am I right?" Marcy grinned back at her. Bonnie turned an interesting shade of pink as she took her own seat opposite and attached a set of electrodes to her own head.

"I'm not going to dignify that with an answer."

"That is an answer."

"Do you have to have the last word every single time, Marceline?"

"Yep."

"You're impossible!"

"And I still have the last word. Are we starting?"

"Yes. Shut up and focus on what I'm thinking. I'm switching the machine on now."

"Shutting up."

Bonnie sighed again but didn't argue and flicked the switch to begin the electrical signal exchange. She tried to think of innocent objects but thanks to her friend's earlier comments she found the first thing she was thinking of was a pair of handcuffs.

"Handcuffs!" Marcy shouted triumphantly. "You're thinking about handcuffs! Whoa, I'm psychic!"

"That's a lucky guess because you were just talking about them! Try this instead."

She tried very hard to think about something else. Tennis balls. Yeah, they were innocent. Sorta looked like a ball gag though, and that wasn't innocent at all, it was actually pretty damn filthy-"

"Um, BonBon, your mind is _disgusting._ Could you not think about tying girls up and doing kinky stuff to them? This brings shoving your sexuality down my throat to a whole new level. I'll retaliate you know, start thinking about Ash and stuff." Marcy told her, blushing just a little.

"I'm thinking about tennis balls." Bonnie lied. "Oh my God, but this is working! What am I thinking now?"

"A big palace?"

"Yes! And now?"

"Uhh... Oh! Building a house with your weird brother!"

"Ned's a sweetheart, he's just really shy and introverted. And yes, building with Ned. Now?"

"Bats flying out of a cave."

"Right again! And now?"

"Dogs? Oh, that's not dogs, that's _doggy style._ Ew, you did that with that one armed chick from your course? She's so weird!"

"Sorry! Accident! I'll just think about something else."

"So much candy. Is that your ultimate fantasy or something? It's a wonder you have any teeth left. Ooh, brushing your teeth! Guess you do that like, four times a day? I bet you're wicked prone to cavities."

They continued in that way for another couple of minutes before something wholly unexpected happened.

 _Oh man what if she can hear my thoughts? Nah, she'd tell me, right? I'm sure she would. Gorgeous little nerd that she is._

"What?"

"What?" Marcy replied out loud, frowning.

"I mean, uh, what was the last one?"

"Oh. Grapefruit. With a tiny dog in the middle instead of one of the segments. You're weird."

 _And really hot. Dammit, why do you have to be hot? I was so comfortable just being straight._

"Right, I think we'll leave it there for today." Bonnie replied hurriedly. "I've got some time booked in here in a couple of days' time if you can come back and I'll try to guess what you're thinking. But these results are fascinating, I'm so happy!"

It was just as she was reaching to flick the machine off; there was a sudden flash of light and then the lab was plunged into darkness. In the same instant there was a stab of abrupt pain through the electrodes and both girls yelled out at the momentary agony.

"What happened?" Marcy asked, and for a split second she didn't realise anything was wrong. Then- "Wait, what?"

"That's-"

"My voice-"

"Put the lights on!"

"What the fuck did you do to me?"

The lights flicked back on. Redhead stared at brunette, panic beginning to grow on unfamiliar features.

"We... we've swapped bodies. _Fucking hell._ This can't be real!"

Next second the fire alarms were ringing and the brunette who'd previously been Bonnie grabbed Marceline's arm (her own arm, _what the fuck?)_ and towed her from the room as the machine they'd been using burst into flames behind them.

"Something must have shorted inside the equipment! We've got to get outside and register with the fire staff, let them know we're safe."

By the time the fire engines came screaming around the corner the whole building was blazing, flames shooting up into the evening sky. No way was any delicate electrical equipment surviving that.

"My research..." Bonnie mumbled brokenly through her friend's lips.

"Never mind your stupid research, nerd. We're stuck like this." Marceline growled back in Bonnie's voice.

...

Hours later they sat huddled dejectedly on Bonnie's bed in her student room.

"I can't be you. I'm not a scientist." Marcy murmured for the hundredth time.

"I'm not wild about being you, you know. How do you even walk in these shoes? Your clothes are so tight! Why aren't you wearing a bra? What's the deal with these weird lumpy things in your shirt?" Bonnie shot back.

"They're called 'breasts', nerd. Most women have them, apart from you, apparently."

"Fuck off. I mean the weird lumpy bits on the end- wait, do you have nipple piercings?"

"If that's the most disturbing thing you can find on my body right now then imagine how much fun it'll be for you when you need to shower me. I've got piercings _everywhere_." Marcy replied. Her trademark impish grin looked weird on Bonnie's face.

"That's-"

She was going to say how gross that was, but then another problem abruptly presented itself. Marcy's phone started buzzing in what was now Bonnie's pocket.

"Answer it, it's probably Ash." Marceline told her.

"But-"

"Answer it!"

Reluctantly she put a hand that was a little longer than she was used to into unfamiliar jeans and slid out the phone, trying all the time not to notice that she was brushing unfamiliar and rather shapely hipbones too.

"Hello?" Bonnie asked nervously when she answered the call.

"Where the fuck are you? I've been standing here for like, an hour."

"Oh. Sorry."

"Tell him you're ill and you'll call him tomorrow and not to come over." Marcy hissed at her.

"I'm, uh, ill. I'll call you tomorrow, ok?"

"You sure babe? I could come over and-"

"No! No, it's fine. I'll call you tomorrow. Don't want you to catch this. I've got the squits." Bonnie added, a little maliciously. If Marceline was going to make her talk to her stupid boyfriend then the least she could do was use a really disgusting cover story.

"Urgh, that's gross. You're lucky you're so hot that I still wanna fuck you. Love you, babe."

"Uh, yeah, Bye then."

She hung up the line, avoiding Marceline's frown.

"He's gonna know something's up. I tell him I love him like, a million times a day."

"Well I don't. So sorry, it's difficult for me to say that even in your voice." Bonnie shot back defensively.

"Look, it's getting late. I should go home." Marceline sighed, too tired and weirded out still to care more about Ash feeling rejected.

"You can't go anywhere! I can't stay here in my room in your body! You need to stay here or my roomies will know something's up!" Bonnie told her with a frown.

"I'm not staying here! And I'm _not_ staying over with you, they'll think we're hooking up in here!" Marcy replied, horrified.

"Stay here, just for tonight. I'll call around other universities, see if we can find the same equipment and try to reverse whatever this is. Unless you want to spend the rest of our lives being experimented on by excited neuroscientists?"

They'd already gone over the pros and cons of going to the hospital and explaining that something completely impossible had happened. Bonnie had immediately shot that idea down; the neuroscientists would have an absolute field day with them, she should know. Or they'd both be declared legally insane and be forced into a secure unit. Both scenarios were equally unappealing.

"Fine." Marceline sighed reluctantly. "I'll come over and get my car at first light and you better be able to reverse this. I'm not getting stuck being a ginger nerd forever."

"I don't want to be a heavily pierced sarcastic asshole forever either." Bonnie muttered sourly. She picked up Marceline's bag and immediately started packing some overnight clothes.

"What are you doing? I have clothes at home. And that's _my_ body, you're not dressing it in your weird nerd clothes! I don't want your giant unsexy grandma panties rubbing up against my junk."

"Fine. Just, try to keep my body in the routine it's used to, ok? I get up at seven and I have a jog around the block, I do a little yoga and then have a light breakfast. Do not feed me anything with lactose in it unless you really want to deal with the situation that arises with my intestines when I fail to digest it. I'll see you tomorrow." Bonnie murmured. She shouldered the bag and grabbed a couple of books before disappearing out the door, leaving Marceline alone in an unfamiliar body.

"Right. One night as a nerd. I can do that." she muttered to herself. "First things first, this place looks like a dirty clothes bomb went off. Time to clean."

She was shoving things away wherever it looked like they might fit but a lot of Bonnie's stuff didn't appear to have a home, so in the end Marceline dragged everything out of her wardrobe and cupboards and set about rearranging it. She tried to sing while she cleaned but Bonnie's throat was uncooperative and she sounded reminiscent of a strangled cat so she stopped and switched the radio on instead, humming along quietly.

It was almost relaxing, organising stuff. She liked being organised and neat; it was what Marceline considered to be one of her few positive character traits. Of course she was cleaning someone else's room so she had no idea what she was going to find and when she pulled one of the drawers on the nightstand open she yelled in shock.

"Ew, what? What even is that? ...Is this some kinda harness?" she asked herself in surprise.

"Bon! You ok in there?" a voice called through the closed door. Oh man, roomies. She'd forgotten.

"Um, yeah, just got a fright. There's, ah, a spider in here."

To her horror the door opened and Finn The Most Annoying Boy Ever rushed into the room.

"Where? I'll get it, don't worry! Just sit on your bed and breathe calm, I got this!" he announced importantly, eyes scanning the room for the fictional spider. Ok, so Bonnie was afraid of spiders and got her roomies to rescue her from them? Would've been good to know that before.

"No, it's fine. It, um, it went out the window." she muttered, trying to block the still open drawer from view.

"But your window's closed." Finn replied with a frown. "What- oh. I'll, um, just let you, er, I gotta go. Bye."

Apparently she hadn't blocked the drawer well enough and he'd caught a glimpse of the exotic looking objects inside. Well now they'd both need therapy to get those images out of the brains. Beet red in the face and still stammering nervously Finn backed out of the room and disappeared. Marcy sighed to herself and closed the door behind him. She meant to close the drawer too but curiosity burned stronger than her admittedly feeble moral code and it wasn't really invading her friend's privacy, right? Not if it was looking at stuff that was used on the body she was currently inhabiting. She slid the bolt across the door, locking it to avoid any more interruptions, before going back to the drawer. She was blushing heavily but curious to see what else was in there.

...

Bonnie wasn't faring any better either. Marceline's apartment was tiny and she lived alone, after the large student household Bonnie was used to it felt like being stuck in solitary confinement. The freakish neatness of the bedroom and obsessively cleaned surfaces were unnerving her too so she'd tried to stretch into her relaxing yoga poses, only to discover that not only were Marceline's jeans the most constrictive items of clothing ever made but also that she had absolutely no flexibility. Annoyed, frustrated and more than a little creeped out Bonnie did the only other thing she knew would cheer herself up. She went to take a shower. But of course, that was weird too.

Turned out Marceline had been joking about the other piercings, which was a relief. She'd failed to mention the huge raven tattoo stretched across her chest though, that had been a shock. In fact stripping down and getting naked in her friend's body had been intensely weird, but Bonnie couldn't exactly avoid it. It was a human body; it had needs like being fed and cleaned, using the toilet and being clothed in things it was used to. The sensation of unfamiliar shapes moving under her clothes as she walked and limbs a touch longer than she was accustomed to had made it a very awkward walk back to Marcy's place. And the feel of lying on a bed both familiar and strange was decidedly weird. Her hair felt too heavy, longer than her own ginger locks and much straighter. It fell across her face in dark sheets if she wasn't careful and got in her eyes and mouth. Marceline must have completely donked her hearing listening to loud rock music too because Bonnie had almost be flattened by a truck she hadn't heard crossing the road.

And now she was standing in her friend's shower, trying to wash the body she was stuck in without staring at it in a creepy way which was proving difficult. It wasn't that she was attracted to her friend, it _wasn't,_ she told herself over and over. It was just that it had been months since she'd seen a naked female who wasn't herself and Marcy hadn't been wrong when she'd pointed out in her oh so subtle way that Bonnie was significantly smaller in the chest department. And _oh God_ they were right there and _pierced_ and she was so very gay, it'd be weird if she didn't look just a little bit, right? And it wasn't like Marcy could avoid seeing her nude anyway, sooner or later she'd need to shower too.

So knowing that it was at best morally questionable Bonnie opened her eyes, intending to look down and maybe have just a quick peek at the body she was trapped in. Instead she screamed in shock because she was no longer alone.

"Hey gorgeous, knew you weren't really sick." Ash smirked, sliding into the shower next to her, incredibly nude with one arm moving rhythmically against himself. "Naughty little slut. You need to be taught a lesson about what happens to bad girls that lie to their men. Bend over and grab your ankles babe, tonight I'm gonna be your backdoor lover."

Large, masculine hands slid down her naked borrowed body and there was something absolutely repellent happening between his legs, Bonnie felt like she might be sick from how disgusting he was. And her self-defence instinct took over completely when her horrified brain worked out what he was implying.

Ash let out a bloodcurdling scream as her fist slammed heavily against his soft, vulnerable balls. He dropped to the floor of the shower like he'd been shot.

"KEEP THE FUCK AWAY FROM ME YOU DIRTY FUCKING PERVERT!" Bonnie screamed, incensed. Who the fuck just let themselves into their girlfriend's shower without asking and told them to bend over? How long had he been standing there watching her, touching himself? Fucking hell, he was so disgusting! She fled from the room, grabbing a towel on her way, and pulled on the pile of clothes she'd left on the bedroom floor in a state of blind panic. She'd just punched Marcy's boyfriend in the nuts hard enough to castrate him and left him crying on the shower floor. She was trapped in her hot friend's body and might never be herself again. She was stuck having definitely not platonic thoughts about the body she was currently trapped in, and she'd had intimate parts of that body touched by a disgusting naked man in a state of deeply disturbing arousal who apparently didn't see anything wrong with ordering his girlfriend to bend over and grab her ankles without asking if she wanted to first. Dressed and pulling on the first pair of shoes she could find, Bonnie grabbed the keys and bag and sprinted for the door.

"Get back here you little bitch! What the fuck is going on?" Ash yelled from where he'd managed to stumble through from the lounge. Too late, she slammed the door in his vile face and bolted away into the rain, heading instinctively for the place she felt safest; her own bedroom. She arrived breathless at her own front door a few minutes later and hammered against the wood, staring back over her shoulder in panic in case he'd followed her. But nobody was chasing her down the street, it was deserted. The door finally opened and _thank God,_ Jake was blinking back at her. She threw herself on him in relief.

"Jake, oh God, that sick fucking pervert _touched_ me and I hit him. He wanted to- I can't even say it, it's too sickening. Urgh I feel so gross! Is Marcy here? Please say she's here. I need to talk to her."

"Uh, hi. This is pretty weird. You are Marcy." he replied, stiff in her arms with shock. "What the hell happened? There's soap in your hair."

"I meant Bonnie. Is she here? I need to stay the night." she replied, mortified that she'd forgotten even for a second.

"BONNIE! GET DOWN HERE, WE'VE GOT A SITUATION!" Jake yelled over his shoulder. A minute later a familiar rusty coloured head peered around the staircase at them.

"Hey, I shoulda known. Come on up, we'll talk in your, erm, my room."

It was weird to hear her own voice without the feeling of her throat moving. Bonnie followed her own body back up the stairs to her own room, sat down on the edge of her own bed and burst into tears.

"Hey, what happened? Why is your hair leaking shampoo everywhere? Why is my sweater on backwards and inside out?" Marcy asked her quietly the minute the door was closed.

"I was in the shower and A-ash tried to t-touch me! He said he w-was gonna teach me a lesson and told me to bend over, so I punched him in the balls and I r-ran." Bonnie sobbed against her own shoulder.

Marcy just sighed heavily, guilt and horror swirling through unfamiliar guts. She should have warned her friend about him but that would have meant admitting to herself just how controlling and borderline abusive he was and she hadn't been ready to do that yet. He'd spent so long telling her she was stupid and worthless that she'd started to believe him.

"I'm sorry." Marcy murmured. "I guess I didn't see it until now. Did you hurt him? Tell me you hurt him."

"Yeah, pretty badly. I think he's probably infertile now. You've got really strong fists." Bonnie admitted quietly around her sobs. "Probably he'll be peeing blood for a few days. Something crunched down there when I hit him."

"Well that's a relief." Marcy replied, still feeling unbelievably guilty.

"I'm not going back there." Bonnie told her. It was weird to look into her own eyes and see how open and vulnerable the expression was in them. She'd never been open with her feelings.

"Stay here for the rest of the night then, I think you roomies already know something weird is going on."

So just for comfort, just because the whole evening had been so far beyond bizarre that they'd completely run out of cope or fight, they curled up in Bonnie's bed together. Because in a world where everyone thought they were someone else, each other, nothing felt right apart from being close together. And neither of them had any strength to be in denial about that any more.

"Hey, Bon?" Marcy asked sleepily, just on the right side of consciousness.

"Yeah?"

"Why've you got a draw full of kinky stuff?"

"Oh. You found those, huh? Cause, um, I'm a bit kinky sometimes."

"Ok. Just asking."

"Marcy?"

"Yeah?"

"Sorry I saw you naked. But you know what? You've got magnificent boobs."

"Thanks."

"I mean that objectively. As your friend. I've seen lots of boobs but yours are really good."

"Yeah, I'm pretty proud of those puppies. Now go to sleep nerd, you gotta figure out a way to switch us back tomorrow."

Bonnie went to sleep curled against her own shoulder and feeling a weight of contentment in her borrowed chest that she didn't want to examine too closely because she wasn't certain which of them it belonged to.


	2. Chapter 2

**Ahhh ok so it's kinda kinky smut. Sorry! I was totally gonna write it cute but then they started getting messy and... well I'd like to say I'm sorry but I'm not really. So, smut! Enjoy? I'll have to update the rating and the summary so I don't risk offending anyone with naked women.**

 **Much love to everyone who took the time to review! You guys are all so sweet! Extra length chapter today because the characters got a little out of hand being naughty. I genuinely hope nobody's shocked or disgusted by this.**

 **Content Warning: sex. Quite graphic gettin' down, implied kinkiness, feels.**

* * *

 _Ok, she's still asleep. Right. Great. Time to figure this out. So what do we know so far? Well, Bonnie's gay. I knew that since the first time I met her, like Finn even introduced her as his 'lesbian friend'. And I'm straight. I mean, obviously, right? We're friends. A straight girl can have a lesbian friend and it doesn't have to get weird, it's the twenty first century. But, it got weird. Because now I'm stuck in a gay body and I'm completely certain that the gay body is the reason those thoughts happened. I mean, I'm straight. I enjoy getting frisky with dudes. Ok, 'enjoy' might be stretching it a bit, it's not like Ash ever set my world on fire. I mean, sex is pretty much an over exploited tool used by capitalism to sell stuff like cars and soap and stuff, it can't be as good for everyone as they make it out to be. Can it? Well maybe for lesbians. I dunno, my body is gay but my head is straight. I'm messed up right now. But if I'm in a gay body and that's making me think about kissing girls and stuff then why did Bonnie freak out and punch Ash last night? Because she's now in a straight body so you'd think she'd be less disgusted by a naked man if the sexuality of my body affected her thoughts too. Ohh but then maybe she's in denial! That'd make so much sense. I'm so good at working this stuff out, I- shit, is that my phone? Fuck._

Bonnie was only half awake but she could hear thoughts that weren't her own echoing in the back of her head. Next second the warm body lying wonderfully close to her in the bed made to move away and she wrapped her arms around whoever it was sleepily, not wanting to let that comforting warmth and intimacy go just yet.

"Get off me, you gotta answer my phone." Marceline hissed at her with Bonnie's voice, and her eyes flew open as the events of the previous day came flooding back to her memory.

"What-" but Bonnie didn't manage to get the words out before Marcy's mobile was pushed into her hands and she answered it in confusion. The caller ID flashed the name 'Daddy' and she groaned internally.

"Hello?"

"Marceline? Oh thank God! Where are you? Are you safe? What happened, what did that boy do to you? I've been looking for you for hours, the police said you were missing and you weren't answering your phone and-"

"I'm fine, um, Daddy. I stayed the night at Bonnie's place, had a row with Ash last night. Wait, why were you talking to the police about me?" Bonnie asked as her brain began to get back up to speed. Across the bed Marcy stared at her in horror through Bonnie's eyes, mouthing 'what's going on?' at her.

"You don't know? Oh honey, I am so sorry. Listen, it's your apartment-"

Bonnie listened in growing horror, trying to avoid Marceline's gaze while she took in the details of what had happened.

"Yes, I'll be right over. Thanks for letting me know. I'll see you soon. Bye."

"What? What is it? He didn't yell, something bad's happened. Hasn't it?" Marcy asked in a rush.

"I'm so sorry. It's all my fault." Bonnie whispered, unable to meet her eyes. "Ash trashed your apartment last night and when your neighbours called the police they arrested him and he wouldn't tell them anything, they thought he'd killed you and hidden the body or something. Your father's been trying to call for hours, he thought you were hurt, he was frantic."

For a long second Marceline just stared down at her hands, looking like perhaps she'd cry or perhaps she'd murder someone. Then she just sighed and shook her head.

"I always knew he was a psycho, it really doesn't surprise me. Guess I just liked that someone liked me, that's still a surprise sometimes." she murmured.

"Oh honey, loads of people like you. You're awesome and funny and beautiful and you always know how to make people laugh, you're so chill it's hard to stay stressed when you're around. You can do a whole lot better than stupid Ash." Bonnie told her gently, reaching across and taking her hand. Marcy just shrugged and pulled away from her touch.

"No use thinking about it now. I gotta go see how badly messed up my stuff is." she sighed regretfully.

"Actually I need to do that. You can't turn up in my body and sort it out, besides you'll need some help."

"Yeah. Yeah, that's a good point I guess. Come on then nerd. You're gonna need to wear some of your own stuff since I shudder to think what Ash did to all my clothes."

They hadn't bothered with modesty the night before while changing for bed, it had seemed pretty pointless since they'd obviously already seen their own bodies in every possible state of undress. But it didn't escape Bonnie's notice that Marceline turned away and changed as quickly as possible, not looking at her friend and trying to cover as much of her borrowed body as she could. She wondered what was up with that or if it was just habit. Bonnie couldn't really remember much of what she'd been thinking before Hunson had called but she got the vague impression she was somehow making her friend uncomfortable.

"Hey, are we ok?" she asked Marceline's turned back gently.

"Yeah. Just peachy." she replied, although her voice sounded a little odd.

"Ok. Just, you seem a bit stressed."

"Maybe because my psycho ex just trashed my apartment and I'm stuck being you and my entire life turned into some next level Freaky Friday shit?"

"Sorry. I just, I want to help." Bonnie murmured guiltily.

"Yeah well you helped enough when you switched bodies with me, donked my relationship and put a ton of weird unwelcome thoughts in my head. So thanks and all, Bon, but I could live without you helping me."

Next second the bedroom door closed behind her, leaving Bonnie blinking alone in surprise, unsure if she should follow.

…

"So. You and Angry Music Girl, huh? So how'd that happen?"

Great, the kitchen was occupied by Jake and Finn, still home because they were on exam study leave. Marceline really wasn't in any mood to deal with them.

"We're just friends, she broke up with her boyfriend last night and now he's trashed her apartment and I'm a crappy friend because I make everything worse." Marcy replied moodily, grabbing a plate from the cupboard she knew Bonnie kept her stuff in.

"Oh. I mean, yeah you're just friends right now but come on BonBon, even Finn's noticed the way she looks at you." Jake replied with a puzzled expression on his broad features.

"What? She doesn't look at me. Marceline is one hundred percent straight, ok? She's definitely into men. So you and Finn can just-"

"Woah, defensive much? This is like the morning after or something. What happened, did you two hook up and now she's freaking out about it?" Finn frowned around a mouthful of cereal.

"No. Just leave it, ok? We're just friends. Gal pals. Mates. Right?"

The brothers exchanged a look over their breakfast but neither of them said anything else. Marcy got herself a plate of toast and in an uncharacteristically forgiving gesture made enough for two and two mugs of tea. She took them all back upstairs to Bonnie's room and entered without knocking.

"Hey. Sorry I was weird. Just, it's sorta messing with me, being stuck in the wrong body and all. I brought you breakfast."

"Oh. Thanks. It's ok, I know this is supremely weird." Bonnie replied from where she'd been sitting on her bed writing on her laptop. "I just emailed my tutors and told them I'm sick and won't be in for a few days, you should do the same. If I have to turn up to your music lectures and pretend I know what I'm doing then we're gonna get found out really quickly."

They ate in silence after that, neither willing to acknowledge the tense atmosphere in the room. After breakfast they left the house, mercifully avoiding Finn and Jake, and made their way back to Marcy's apartment. As they walked occasional thoughts that were not her own drifted into Bonnie's brain, and every time it happened she tried to ignore it and not react because she was certain the other girl didn't know it was happening.

 _Maybe I'm just super attracted to myself? I am cute, sometimes. But what the hell, how can Finn have noticed something I don't even do? Idiot boys don't know what they're talking about._

Oh. Oh no. Finn must have said something to her about his ridiculous theory that Marcy was more than a little in denial about finding girls attractive. Bonnie herself had told him time after time that no, they didn't have sexual tension. They just argued a lot. It wasn't the same thing, right? And sure she was perfectly capable of finding her friend's body attractive, it didn't mean she liked her for her, just that it'd been absolutely ages since she'd gotten physical with someone hot. They were just friends. And that was all.

...

It took the best part of the day to straighten everything out with the police, reassure Hunson that his daughter wasn't lying in a ditch somewhere with her throat cut and clean through the smashed up crap of Marcy's apartment. She was going to need a brand new bed and new clothes, Ash had apparently taken out his rage by pissing all over them. Bonnie was savagely glad to see that there were definite streaks of blood in the mess; it must have been like pissing razorblades for him. Still she couldn't help but feel terribly guilty for everything that had happened since it was basically her fault. Every time she tried to talk to Marcy about it the other girl changed the subject though. Bonnie wasn't sure if her friend was angry with her or not.

By the end of the afternoon Hunson had to leave and attend to some business meeting or other. He repeatedly thanked 'Bonnie' for coming and being such a good friend to his little girl, unaware that he was speaking to his own daughter the whole time. When they were briefly alone he glanced around and sidled up to her, coughing awkwardly to get her attention.

"Excuse me, erm, Bonnibel. I just wanted to ask, well my daughter talks about you a lot and I wondered if, um? Well she's mentioned a couple of ex-girlfriends of yours in the past... And I'm not against that sort of, er, lifestyle, but Marceline and I don't really have the kind of relationship where she feels she can tell me things like that. I wasn't sure if you and she were, you know, an item? So just, I don't know what's happening or if anything is happening, but hypothetically, if something were happening and you were to hurt my daughter the way this idiot boy Ashley has done..."

He trailed off and tilted her a significant glance. Marcy stared back, utterly _horrified_. Had her father done this to other people too? He could pretend she didn't exist for months when she was inconvenient for him but now he was putting the scares on her definitely platonic but very attractive friend?

"Nothing's happening. We're just friends and she's completely straight. Why would it matter if we were seeing each other anyway? Are you threatening me?"

"No, not at all! Simply looking out for my daughter. Well, I'd best be off, don't want to be late for my meeting." Hunson added in a falsely jovial tone. "Tell Marceline I said goodbye. She's on the phone with someone from the university and I don't want to disturb her. I feel sure I'll see you again, Bonnibel."

And with that he strode out the door and disappeared.

"Sure, can't have your business meeting disrupted by my entire life imploding but Heaven forbid you neglect to leap to conclusions and try to scare away my friend just because you happened to remember her name. Same old selfish bastard." Marcy muttered to herself, picking up his discarded broom and beginning to sweep up the shattered remains of her possessions.

She'd cleared away most of the broken junk in the kitchen and was sighing over the slashed ruin that used to be her sofa when Bonnie returned from where she'd been talking on her mobile in the stairwell. Marceline maybe wasn't the best judge of her own face since she saw it less often than most of her friends but she thought those familiar features looked a bit pale, a bit frightened. That was weird; she wasn't accustomed to looking frightened.

"What? More bad news?" Marcy asked with another sigh. She was trying hard not to take it out on her friend, Bonnie was literally the only other person on the planet who stood a chance of understanding how she was feeling, or why.

"You could say that. I've just gotten off the phone with the university's administration department. The only good news is that I'm not liable for the fire, it was an electrical surge in the grid and, I dunno, something to do with a momentary overload of the power system, it's not really my field so I'm not sure how to replicate it. But that's the problem. We can't replicate it. Even if we somehow managed to get to use the same piece of equipment somewhere else then there's no way to be certain we'd be able to unswap ourselves. We might be stuck like this forever."

"No." Marcy said, flat out refusing to believe it. "No, this is science, this is your whole deal! You've gotta be able to fix this! I can't be you forever! There must be some way, some book you can look in-"

"Seriously? You think there's a textbook for what to do when you accidentally swap bodies with you gorgeous but annoying friend? I have no idea what to do next! I don't much want to be you forever either! I want my body and my life back. What happens when the semester ends, do I go home to your father and dutifully listen to him drone on about tax law for two months? Am I supposed to try to finish your music degree? Have you got the first fucking clue what the difference is between a cerebellum and a hippocampus? You're going to ruin my neuroscience degree and I'm going to ruin your music career and this is completely fucked and-"

Bonnie stopped to draw breath and when she thought about it that awful prickling in the corner of her borrowed eyes was back, like when she'd burst into tears last night. She slumped to the floor, defeated, and didn't resist at all when she felt her friend sit carefully next to her and draw her into a hug.

"Hey, I just meant that if anyone can work this out then it's you." Marcy soothed. "Just, I know it's scary, I'm scared too. But this isn't natural or normal and it's bound to get fixed eventually, right? At least we have each other."

It was when they were physically close, Bonnie realised. When they were walking side by side or lying next to each other in the bed, hugging on the floor or something. That was when she could hear her friend's thoughts.

 _I'm completely certain she didn't mean to call me 'gorgeous'. Anyway I'm straight, what does it matter? Accept the compliment and move on. I mean, ok maybe I'm just a tiny bit bi-curious. Especially about her. And I'm single now, oh hell. I wonder if her lips are as velvety to kiss as they look in the mirror? Dammit, I may be a little bit massively queer for my best friend._

"You know what we need?" Bonnie asked quietly, trying to figure out what to do with that information.

"What?"

"Alcohol. And food too, of course. But yeah, I am far too sober to deal with this right now. We're going to a bar. Come on."

She stood and pulled Marceline to her feet too. It was happy hour at the student union and there were seven or eight Cosmopolitans with Bonnie's name on them.

...

It was dark when they got back to the house and apparently deserted. Jake's shoes were gone from the hall and Finn's car keys were missing so they summarised that the boys were still out somewhere. So that left just the two of them alone in the house, pretty wasted and with so much tension between them the air almost popped with it as they made their way upstairs.

 _Wanna try it, go on, just ask her, what's the worst that could happen? Oh God what am I even thinking? I'm not gay! So very gay for her though. Fuck! Ohh yes, fucking would be good. No, what? Urgh I don't know what to do. She was hot even before all this and now we're stuck being each other and I don't know if I fancy myself? Is that actually possible? Or is this body just attracted to that body? Or am I actually crushing on the girl currently piloting my body? Am I a narcissist, a slave to the hormones in my new bloodstream or just_ _really gay for my friend? How do I work it out?_

"Do you, ah, want a snack or something?" Bonnie asked quietly, shoulders tense from what her friend could see of her in the low light of the single bedroom lamp.

"No." Marcy replied in a voice tight with repressed- something. She didn't want to think what it could be. Tension or something.

Something in the back of Bonnie's brain whispered; _fuck it, I really want to kiss her,_ and she had no idea if it was her own subconscious or the stray thoughts she'd been hearing all day. But thanks to the numbing effect of the cocktails she didn't really care which it was because just like the night before nothing really felt right until they were close and perhaps it was her mind wishing to reunite with its body or perhaps it was just attraction plain and simple. The worst that could happen was she'd be let down, she could handle rejection. So without stopping to think twice Bonnie crossed the room in two strides and when her friend looked up from where she was sitting on the bed she caught hold of the other girl's face (her own face, it was still a little strange to think about) and kissed her thoroughly. For one glorious, dizzying moment Marcy kissed back and Bonnie wasn't sure what that meant but she was more than happy to find out. But then there were hands on her shoulders pushing her gently but firmly away and confused eyes staring up at her.

"Wh-what was that?" Marcy gasped, looking breathless and windswept like she'd just sprinted somewhere.

"An experiment." Bonnie murmured quietly, wondering what the hell she'd just started. "I felt like it would be a good thing to try. Weren't you ever curious to know how your own kiss felt?"

"I guess." Marcy shrugged, still looking like she'd just been slapped instead of kissed. "But I'm straight. You know that."

"Yeah. Sorry. It was just an idea."

They sat in silence for a while longer before Bonnie gave in to the urge to do anything at all to break the tension and grabbed the remote for the small TV set she had on one side of her desk. Sometimes she liked to watch documentaries while Finn and Jake were using the TV downstairs to play football games. After a few minutes of staring aimlessly at some dancing programme Marcy took a breath, opened her mouth like she was about to speak, then closed it again with a small sigh. Bonnie waited, she'd say what she had to say eventually.

 _This is torture. Grow a pair, talk to her. Or go fap in the shower, do something for fuck's sakes! But you are not gonna just sit here like a useless lump feeling feelings all over the place. Shiiiit that kiss was good. How can I tell her I'm not actually a nun and she's so fine and I just wanna try stuff out? Goddammit open your mouth and ask her to screw you already!_

"Listen, Bon, this is weird, right? I mean, we're never gonna tell anyone about any of this ever, are we? I'm definitely not, I don't wanna sound like a crazy person. But I was thinking, yeah? If we're experimenting and I'm probably never gonna have this opportunity again and look, you're in my body so it'd really just be pretty much the same as what I do in the shower from time to time. Do you wanna, y'know, try it out? I've just been thinking about it a lot and I wanna see what it's like, you know? Cause that kiss was pretty amazing and you know what you're doing and I just, oh man this is weird, right?"

Bonnie looked at her, weighing it up. What was the worst that could happen? Marceline was right, it was her body.

"Are you asking if I wanna experiment some more? Like, physically?"

"Uh, yeah. Like, I just thought, since that's my body and all. I just, um, oh man not in a gay way. Y'know?"

"Gay sex in a not gay way. Right, so like, fuck me but no homo?"

"Yeah!" Marcy replied, relieved she'd managed to communicate her meaning without having to explain much.

"You're an idiot. You really think I'd do that? You don't expect that I'd want intimacy and mutual feelings to be included in my sex life?"

"Oh. Yeah, I mean, usually? But this would just be an experiment. I don't wanna offend you! Just, I wanted to try it on me and see what it's like and your body is already used to doing stuff with girls. Doesn't that make sense?"

"So you want to experiment with me."

"Yeah."

"Huh. Experiments with girls. I suppose it's what a lot of straight girls do at university. Fine, this is the weirdest thing that has ever or could ever happen to me but I could go for a little casual experimentation. But we do it by my rules. Agreed?"

A jolt of warmth shot through Marcy at those words; it was almost painful in how badly she wanted it. It was all the gay body's fault of course but when else would she ever get to experiment with homosexuality consequence free like that? Girls were so soft and warm and she wondered more and more if the curves of an undeniably feminine body moving against her would stir something in her. Given the evidence she suspected that they would; that magnificent kiss had done more than just leave her breathless and set her heart hammering.

 _Shit. Fuck. What am I doing? Oh God if she says she's joking I might die, I want this so bad._

"Your rules? Um, what are your rules?" Dammit it was almost painfully hot just to ask that. Bonnie smiled back and it wasn't a gentle or sweet smile, it was the kind of smile a shark wore when they noticed an injured seal. Marceline had a sudden epiphany about why some people found her intimidating; that expression staring back at her from her own face wasn't something that inspired trust. But oh hell, it was sexy. Yeah, maybe she was just attracted to herself, mega narcissistic.

"You do exactly what I say. Without question or hesitation; I'm the scientist here and you're an experimental specimen. And you don't question me or my methods, you obey like a good girl. You tell me straight away if there's anything you don't want, any lines you won't cross. And you remember the safe word, I usually use 'peppermint'. Can you follow those rules?"

Marcy nodded, not quite trusting her voice to stay normal if she opened her borrowed mouth and tried to speak. It was entirely possible that she'd never been quite so turned on by the thought of someone ever in her life.

"Good. Now, strip." Bonnie commanded her, still with that predatory gleam in her eyes.

"Uh, right now?"

"Yes. You said you'd follow my orders and not question me. Or do you want to stop?"

She shook her head; no, if she stopped now she'd spend the rest of her life obsessing over it and probably going crazy wondering what would have happened. So Marcy followed orders and began to shrug out of her clothes, trying to stay subjective and not blush. She stretched out naked on the bed, shivering and feeling an odd mix of anticipation and vulnerability while the other girl watched her with hungry eyes, assessing and calculating.

"It's a little strange." Bonnie murmured, eyes raking across pale flesh. "I've never seen myself at this angle, I'm really quite pretty, aren't I? Well, at least I know what sort of things I like. Open the draw on the nightstand, the one you were so shocked by last night."

Oh hell, what could she do but obey? Well, she could say no obviously but she didn't want to. Heart hammering dangerously fast Marcy did as she was told, opened the drawer and stared down at its contents.

 _Holy cow that's a lot of kinkiness._

"Now pick whichever you want to play with first. I'd recommend the glass, it's spectacular."

Yeah, the glass one was pretty exotic looking. It had a gentle curve to it and looked pleasantly non-phallic, for a- well, one of those. She wasn't sure she could even think that word without stuttering and blushing like Victorian virgin. So half terrified and half dying of need Marcy picked the glass one she'd been recommended out of the drawer and turned to her friend with it, not quite able to make eye contact.

"Look at me." Bonnie commanded in a voice that sounded just a little strained. Marcy reluctantly raised her eyes to meet her own gaze in the face that until recently had looked back at her from the mirror every morning. "Do you want this? Are you certain?"

Well, was she certain? For a brief second Marceline considered what would happen if she said no. She'd dress again and they'd just, what? Cuddle? Watch TV? Those things sounded good too. But the thought of just stopping and going back to that uneasy, tense not-quite-just-friendship, well that was just awful. No, they needed this. Even if it was horrible, just to clear the air. And from the way her borrowed body was reacting Marcy was sure it wasn't going to be horrible.

 _So badly it's painful._

"Yeah. I'm certain. Where do you want me?"

"Right here. Lie down and get comfortable; we begin with you closing your eyes and describing how everything feels. The most important part of experimentation is accurate and thorough observation." Bonnie murmured in her ear. Next second there were lips grazing the side of her throat and cool hands sliding down her arms and sides and Marcy's brain fizzled to shocked and amazed blankness. Even the constant whispering of how badly she wanted it in the back of Bonnie's head was quiet, the mental equivalent of a sharply drawn breath of surprise and pleasure.

"Describe it." Bonnie reminded her after a minute where all her friend did was gasp a little and writhe beneath her touch.

"It, uh, it's nice. Really nice. Kinda, tingly? Like a low electric current. Turns out your skin is really sensitive."

"And is it affecting you at all?" Bonnie purred.

 _It's slowly killing me. Don't stop, don't ever stop._

"Uh, yeah. Yeah, I'd say it's having a pretty big effect." Marcy replied out loud, halfway between turned on and mortified.

Bonnie just laughed a little, low in the throat and edged with dark delight. Her hands slid further down and she was rewarded with a gasping moan from her friend and a string of mental swearwords in the back of her head.

"Feels, _ah fuck_! like fire. Like electricity and fire, sorta mixed together. Like I can feel my pulse where you're touching. It's warm, and, I dunno, I can't describe it."

"Do you like it? Do you want me to stop?"

"Yes. No. Yes I like it, no I don't want you to stop. I want more."

 _Fuck the line between gay and straight. Fuck societal norms of what I should or shouldn't enjoy. I want this. I want her. I don't think I've ever wanted anything so badly in my whole life._

"Do you want to try everything?" Bonnie breathed.

"Yes. Everything."

"Good. Because that glass toy isn't for you, not to start with. I want to see if you can please me first, you've gotta earn it. So now you're gonna undress me and do everything I tell you to. Yeah? Is that what you want?"

"God, yes."

No consent had ever been so eagerly given, no promise so thoroughly fulfilled. Because Bonnie was nothing if not a thorough scientist and nothing but the strictest experimentation would do. When her eyes finally rolled back into her head and a sharp cry she was completely beyond holding back broke her lips somewhere in the back of her head she could hear whispering, hear her friend's thoughts.

 _Woah. So the experiment was a success? I don't think I've ever seen anything so delicious as my best friend coming just for me, she tastes so amazing. God I hope I've been a good enough girl to see if she wants to carry on the experiment._

Oh yes she wanted to carry on the experiment, the only way to make sure their results were accurate was to replicate them at least three times. Every good scientist knew that.

...

Morning dawned with the golden bars of sunlight pushing through her threadbare blinds to stab Bonnie's eyes and wake her far too early like they always did. She slid out of bed, nude and still half sleep, pushing hair out of her eyes and yawning, stumbling into her robe to go visit the bathroom and get a glass of water. The pounding in her head announced a hangover brewing but she wasn't too surprised by that, it was a Saturday morning and she was a student, she'd certainly had worse.

There was snoring drifting down the hall from Jake's room and she knew that meant Lady had stayed over; Jake didn't snore and his girlfriend liked to pretend she didn't either but the only time it sounded like someone running a sawmill in his room was when the slight Korean woman stayed the night with him. Bonnie smiled to herself a little fondly. Looked like she wasn't the only one who'd seen some action that night. There was an unfamiliar girl's jacket hanging in the hall too when she peered down the stairs, either Lady had started wearing stonewashed denim which didn't seem likely or Finn had brought someone home too. Well, good for him, Bonnie figured. It was about time he got over his last awful break up.

By some strange quirk of design the three bedrooms were upstairs and the bathroom was downstairs meaning that early morning bathroom trips meant walking through the greater part of the house. Something felt a little odd to Bonnie as she walked but she wasn't quite able to put her finger on it. Not odd, exactly. Like, the opposite of odd? There was some oddness she'd been vaguely expecting and it wasn't there. She frowned to herself and pushed the bathroom door open, taking a moment to examine her face in the mirror over the sink. She'd need another haircut soon or her hair was gonna end up as long as Marcy's-

"MARCY WAKE UP WE SWITCHED BACK! WAKE THE FUCK UP! SERIOUSLY LOOK AT YOURSELF WE'RE US AGAIN!"

Marceline opened her eyes eventually, it was annoyingly difficult to sleep through that much yelling and shaking. Bonnie was staring back at her, blue eyes wide and ginger hair flying everywhere in her excitement. Wait-

"Holy fuck, I'm me again!"

"We switched back in the night!"

"We- last night-"

The memory of what else they'd done in the night slammed into both their brains at exactly the same moment.

"I, uh, I should go. Gotta clean up my apartment some more and stuff." Marceline mumbled, sliding out bed and grabbing the pile of borrowed clothes she'd so eagerly discarded the night before.

"Oh. Ok. Um, are you coming back?" Bonnie asked, suddenly amazingly unsure of herself and where they stood. What had she asked herself last night? What's the worst that could happen? Well she could lose a really good friend that she really liked, for a start.

"I dunno. Maybe. Might just take a bit of time, y'know, sort my head out. I'll call you."

And then Marceline was gone and Bonnie sat alone in her room, shocked and confused, staring at the still warm indentation in the sheets where her best friend and now maybe her lover had been just a few moments before.


	3. Chapter 3

**Final chapter I'm afraid, folks. Thank you so much to all the lovely people who took the time to review, you're all absolutely gorgeous. And a special huge thank you to the literally beautiful Schwarzeil for requesting this story and putting the idea into my head! It's been a real pleasure to write.**

 **As ever, feedback is so very appreciated. Send reviews if you can because it's so rewarding to know what people think of my stories.**

 **Content Warning: angst, turmoil, senseless acts of violence against amps and flowers.**

* * *

Bonnie's heart leapt into her mouth when the line finally connected; weeks had gone by and her calls and messages had been left unanswered. It was late and she'd been planning on just leaving another pointless voicemail but it looked like someone was actually gonna answer this time.

"Marcy?"

"No, who is this?"

"Um, it's Bonnie. Is Marceline there?"

"Kid, I have no idea who you're trying to get in touch with but she gave you a wrong number."

"Oh. Sorry."

She hung up the line, put her phone to one side and rested her head in her hands. So Marcy had changed her number and hadn't told her? Well she hadn't spoken a word to Bonnie since she'd disappeared out of her life so that wasn't really surprising. It hurt like a knife through her guts anyway though. Bonnie had already cried herself dry over it and she couldn't summon any more tears about how badly she'd messed everything up right then. Perhaps if she'd been able to cry about it some more she'd have felt better. Instead she curled up on her side and stared at the empty pillow next to her on the bed. Underneath that pillow was her final shame; she still had the t-shirt that she'd pulled on in a panic under her sweater the night she'd fled after punching Ash in Marcy's body. It was a little too big for her, some stupid cartoon of an album cover with dead marshmallow faces impaled on skewers and snakes and stuff. A little of her friend's scent still lingered in the black cloth and some nights pulling it over her head and inhaling it was all that got Bonnie to sleep. Even then she was plagued by dreams where they were still friends, where she hadn't screwed it all up, or even worse those awful nightmares where she relived the night she'd done what she could only mentally call The Bad Thing. Thinking about it in any further detail than that caused her to curl up in horror and want to tear her hair out.

She couldn't help but think of all the times she'd spent with her friend, over and over again. The day they'd met Marceline had turned up in the fancy car her wealthy father had bought for her, rolled her eyes at the half packed mess that was Bonnie's room and proceeded to sort everything neatly into boxes then with Finn's help carry them out to the car. Bonnie had paid the petrol and bought food for everyone to say thank you and somehow Marcy had ended up staying until four in the morning watching reruns of Dr Who with them. And they'd become friends. After that every time university got too stressful and she needed to chill for a while Bonnie would call Marceline and they'd hang out in the park or the bar or go shopping together, go to the cinema and one memorable time to a rock concert because Marcy was horrified that Bonnie had never seen a band live. And very slowly, without her even noticing, feelings had crept in along with friendship. Bonnie hadn't even been aware of them until the door was closing behind her friend and she was sitting alone in the bed they'd shared intimate moments in. It had felt very much like being broken up with so by obvious logic what they'd had before was way more than simple friendship. Against all the odds Finn and Jake had known something that Bonnie hadn't; if she'd had any motivation to do anything at all she'd have told them so. But now Marceline had disappeared completely and Bonnie felt like her world was slowly dissolving without her friend.

"Wherever you are I hope you're looking after yourself." she murmured to the shirt, feeling stupid but also a bit like she might just be able to reach through their mental link to reach her friend. "Hope you're happier. Hope you managed to get your head straight."

Across the city in the small room she now occupied at her father's house Marceline turned over in her sleep and reached out as though she could feel the cloth of her old shirt, murmuring her friend's name and like she did every night.

...

It had been easy to overlook, at first. When they were spending a lot of time together and doing pretty much the same things it had just been like random thoughts, the sensation of cloth against skin but not from the shirt she was wearing, the image of food she was sure she hadn't eaten that day. Now it was undeniable. Marceline was somehow still psychic from the accident and apparently she was exclusively tuned to her former best friend. It made pretending the other girl didn't exist very difficult.

 _Tears still wet on cheeks. Well known sheets against her face, head under the pillow. And the familiar scent of her friend's shirt. The only comforting presence she had now. Regret. Self-loathing. And a pain like a hole in the very centre of her._

It faded after a second but Marceline was under no illusions about what her friend was feeling. But how could she go back? After everything she'd done, all the ways she'd disgraced herself, how could she face Bonnie now? At first she'd really just needed time to process it all because her first thought on being woken that morning was that she could still taste her friend's kiss on her mouth and it was wonderful, maybe being in a gay body wasn't too awful after all. And then she'd discovered that she was in her own body. So those thoughts and reactions were entirely her own. And everything came back to her, there wasn't a tiny detail of their frantic coupling the night before that was censored or blurred by the alcohol. She remembered everything. She regretted nothing. But it was still a huge shock to discover that she was potentially a lot less heterosexual than she'd thought. That the reason guys had never set her world on fire was because what she craved were feminine curves and velvet soft lips, smooth skin and slender hands. Because just the feeling of a girl's fingers tangling in her hair and guiding her, showing her _right here_ , that was hotter than literally anything else she'd ever felt. So she ran away and took some time to think about this monumentally world changing discovery. And apparently Bonnie's self-confidence and ability to interact with the world had imploded. So how could she go back? What could she even say?

She shook the thoughts and regrets free from her head and tried to focus instead. She was late, she had to go. So Marcy shouldered her bass and sprinted for the door, trying to keep her mind on band practice and remembering the lyrics and not on the way her friend's eyes rolled into the back of her head and back arched when she moaned her name. Her own eyes, her own back. It was still so confusing but the weirdness of being abruptly shoved into the wrong body was eclipsed by the weirdness of watching someone else get off in that body through their own eyes. And knowing it was her best friend, knowing it was all for her and she had that power, could cause such extreme reactions in another woman-

Marcy missed her step and almost fell off the pavement. She snarled at herself in sudden anger and shoved the thoughts roughly away. No. Band practice, music. Straight, at least mainly. Not thinking about those delicious things they'd done. By the time she'd made it to the practice studio it was raining and she was soaked to the skin and in a foul mood.

"Yo, we thought you'd got lost." Bongo greeted her as she entered the room.

"Go fuck yourself." Marceline growled back angrily. The other band members shared a look and Keila shook her head minutely, nobody wanted to be in the firing line when their singer was in a bad mood.

They ran through a full set of original material before moving on to some covers, the same ones they'd been working on for a while. It was tense in the studio, nobody spoke much between songs and nobody said a word when Marcy forgot the lyrics or missed a note. Everything would have been fine if they hadn't decided to try a new tune, one they'd only just started working on. It was a jazz and funk inspired song and Marcy had been so proud of herself when she'd written it, it was the most advanced thing she'd ever attempted. If she'd stopped to think about it playing that song on that day was always gonna end horribly but Marcy was trying her hardest not to think at all.

She missed one note and then the next one and then because she was angry with herself for it she missed her cue to sing and it was just too much. There was an image in her head of Bonnie's room and her shirt again and then the crystal clear memory of cool fingers sliding along her stomach and down her thighs while intoxicating kisses took her breath away. Next thing her boot was crashing through the front of the amplifier in a thoughtless expression of rage and she was screaming instead, the other band members had stopped playing and were staring at her while she trashed her equipment. Maybe that's how Ash had felt when he'd taken it out on her apartment, she thought distantly. She tried to summon enough guilt to feel bad for him but honestly if he'd been lying dead in front of her she couldn't have brought herself to care. Dammit she hadn't liked anything about him, why had she ever been with him? Why was she wasting her time with boys when Bonnie was right there the whole time? Too angry and confused, too instantly ashamed of her violent outburst, Marcy unhooked her bass and fled the room. She stopped on the fire escape at the back of the building, cool air stinging her lungs as she sucked in huge breaths to try and find some calm.

It was raining harder than ever and her jacket was still in the studio, Marceline was shivering and soaked to the skin in minutes. She sat on the steps leading down to the alley behind their studio and pulled her thin cotton hood up in a futile attempt to keep the rain off her face. Then she put her head down on her knees and screamed wordless frustration at herself.

"Hey. Keila's gone home and Bongo's so pissed at you he can't face you right now. You gotta get your Daddy to pay for a new amp so we don't get banned from the studio."

Guy's voice floated through from the doorway behind her but she didn't look up, just hugged her cold knees tighter and tried to stop existing. Suddenly the rain stopped splattering against her back and someone sat next to her. She looked up; Guy was peering at her sympathetically and holding a large umbrella over them both.

"What's going on? Is this about your moron boyfriend?" he asked gently.

"We broke up. Then I got really fucked up and slept with my best friend and now I don't know who I am anymore." Marcy replied numbly.

"Oh. That's shitty. So why'd that mess you up then? Seems like you're pretty much the same person to me." Guy shrugged.

"My best friend's a lesbian."

"Oh. Well, you're still you. You just like girls. So? It's no biggie." he said after a second, staring out contemplatively into the rain.

"But I'm not a lesbian. And I dunno if I can still be her friend now. But not being her friend is torture, I miss her literally all the time, and like, I can't stop thinking about that night. It was literally the best lay of my entire life. But I'm not gay, I'm certain of it. Probably? Fuck, I don't know! But I miss her so much, miss just stupid things like hanging out and talking complete bullshit to each other, messing with each other. I dunno what to do, man." Marceline admitted in a small voice.

"Sounds a lot like you like her. And you've got way more feelings than just fucking, right?" he asked, offering a small smile at her reluctant nod. "And she likes you? And you're both single? Then where's the confusion? You don't need to be fully gay to date another girl. Maybe you're bi. Or pan. Or just, really queer specifically for her. Does it matter, if you both love each other?"

"I guess not. Just, this is a big thing to work out. I suck at talking about my feelings at the best of times. And what it she doesn't feel the same? What then?" Marcy muttered.

"The fuck should I know? I'm not a therapist." Guy replied. "But if it was me I'd be there _right now_ , telling her how I feel and seeing how she feels. I mean, you're never gonna know if you never ask, right? Maybe you'll just date for a while then break up. Maybe you'll be sharing a bedroom in your retirement home one day. But if all you do is kick the shit outta amps and mope and avoid her then I can guarantee she won't be in your future. So it's a choice between definitely not having her or possibly not having her. I know which I'd go for."

Guy raised his arms to protect his face but it was too late, she'd grabbed him and kissed him roughly on his stubbly cheek.

"You're a weird little dude and you look far too much like Shaggy from Scooby Doo. But dammit, Guy. You're a secret love guru." Marceline told him, still holding him rigid with arms soaked and heavy from rainwater.

"You're welcome." he muttered, rubbing his cheek in confusion as she jumped up and ran off into the rain.

Neatness was totally her deal, Marcy thought as she jogged along the street. But planning ahead? Maybe not. She'd left her jacket at the studio and it currently felt like several buckets of ice water had been poured over her but she didn't have time to stop and go back for it. She had feelings to confess. There was just one thing she needed first, because even if she was totally acting on impulse she was gonna do it as right as she could. There was a corner shop up ahead, not as classy as she'd wanted but it would do. She jogged in, dripping all over their shiny clean floor, and squinted around in the sudden bright light.

...

 _Maybe she's asleep? Her light is off. Maybe this was a bad idea. Or a really good idea. Won't know if I don't try. Ok. Not gonna ring the bell, don't want Jake to pummel me into the ground or Finn to try to hit me and embarrass himself. Throw a pebble at the window! Genius! Right, pebble, pebble, they never have to fucking scrabble around on the ground looking for a pebble in movies. TV is so much bullshit. Ew is that dog shit? Man this street is a dive. Right, I'm asking her to move in with me as soon as possible, this place blows. Huh, no pebbles. Small stick though. Does it matter what I throw? I just need to wake her up._

Bonnie sat bolt upright in bed, heart hammering. That voice in the back of her head had been silent for weeks and now she could only surmise that Marceline was standing right outside her window debating the pros and cons of throwing a stick or possibly dog mess at her. What the literal fuck? It had only happened when they'd been touching or really close together before. Was the connection getting stronger? She rushed across to her window and flung it open, just in time to be hit in the forehead with a stick.

"OW! What the fuck are you doing?"

"Sorry! Oh man, I was trying to hit the window! Are you ok?"

"The door's open. Come up. I think we gotta talk." Bonnie sighed, not quite able to make out Marcy's shape past the hammering rain and her suddenly watering eyes. Probably it was from the pain of being hit in the forehead, she figured. Definitely not crying.

Bonnie sat on the edge of her bed and tried to think. What was she gonna do? She'd gone through this exact scenario and a thousand others in her head over and over constantly since Marceline had left but now she had absolutely no idea what to say. Was she angry? Elated? Nervous? All of them? Yeah, all of them, she figured. There were footsteps on the stairs. Bonnie's heart tried it's hardest to break its way out of her ribs and flee in panic. Ok, so her overwhelming emotion was panic, and maybe a little fear. She held her breath as the footsteps stopped outside her door for a second.

 _Turn the handle. You gotta face her. Come on you fucking coward. What's the worst that she can do? I don't think she's gonna stab you. Just tell her._

Bonnie held her breath. The door handle turned. And then she was face to face with Marceline, shaking her soaking hood back from her face and trying to smile a little nervously.

"I brought you flowers." the taller girl mumbled, holding up a bouquet shyly. It was actually several bouquets, the shop hadn't had any big ones so she'd bought as many as she had change for and wrapped them all together. It was an odd mix of flowers and colours, some of them different lengths and all of them soaking from being carried in the pouring rain. Bonnie stared at the shapeless bouquet that was thrust into her hands and dripping steadily on her pyjamas.

"Flowers." she replied quietly.

"Yeah. I, um, y'know. Say it with flowers?" Marcy tried.

Bonnie looked down at the flowers, then back at Marcy, then down at the flowers again. Abruptly her overwhelming emotion was fury.

"FUCKING FLOWERS! NOTHING FOR THREE WEEKS!" she screamed, hurling the bouquet at Marcy's face, too angry to care that Finn and Jake could probably hear them. "THREE FUCKING WEEKS AND YOU THINK YOU CAN JUST WALTZ IN HERE WITH A BUNCH OF FUCKING FLOWERS LIKE NOTHING HAPPENED? HAVE YOU ANY IDEA HOW UPSET I'VE BEEN?"

"Yes." Marcy replied quietly. "I do. I could feel it; I could feel the things you were feeling. In my head, like how I could in the experiment. I just didn't know how to tell you how I felt."

"And how is that? Ashamed? Angry? Fucking _betrayed?_ " Bonnie snarled back, unwilling to give up her cathartic fury now that she'd finally let it boil to a head.

"Yeah. Well not betrayed, I never felt like you did anything I didn't want. I just, I had to think." Marcy replied, still in that calm, quiet voice.

"You could have said that! It would have taken you all of five extra seconds to say 'hey I gotta go think but I'll be back so don't think you'll never see me again'. I went to your apartment but someone else is living there now, I tried to call but you changed your number, I had no idea where you were!"

"I stayed with my father because I didn't wanna be in that apartment any more, my phone broke a week ago so I got a new one and I was always coming back, Bon! I just needed to-"

"Think, yeah you said! I missed you, you stupid bitch! It _hurt_ when you left; it was like losing something really important." Bonnie finished at a mumble, unsure she should tell the other girl that it felt entirely like watching someone she loved really deeply walk out of her life forever.

Marceline blinked, there was a thought that didn't belong to her drifting through the back of her mind.

 _Two girls lie in each other's arms, staring into each other's eyes. One strokes the hair back from the other's face and breathes, 'I love you'._

"I, um, Bonnie, I'm sorry. I didn't want to hurt you. I needed to work stuff out. And now I did. And I'm back. I've got something I wanna say but, uh, I thought I had it all worked out but I dunno how to say it now."

Bonnie opened her mouth to reply but didn't get the words out before another stray thought hit her.

 _I can barely even think it, how am I supposed to tell her that I think I might be more than a little in love with her? That if people think I'm lesbian too then fuck it, I'll be an out and proud lesbian for her? I want to tell her. I want to be strong. But the words won't come out, what the fuck is wrong with me?_

That was unexpected. But not unwelcome. And it just made things easier, so much damn easier. Bonnie didn't want to even consider how awful the argument would have been if they weren't still mentally connected. Decision firmly made, she stepped forwards and just like that night three weeks before she didn't allow herself to think about it or question it, just leaned ever so slightly up and pressed their lips together. A blanket of pure serenity fell across her mind, as though a part of her that had been missing was finally back where it should be. It felt a lot like coming home.

"You're soaking wet and freezing." Bonnie murmured against Marcy's chill lips. "Come on, we've gotta get you out of those wet clothes."

"Trying to get me naked _again_ , nerd?" Marcy replied softly, resting their foreheads together and staring into Bonnie's eyes with a gentle smile on her lips.

"I don't want you to get sick. Honestly? I think I left some of myself in you when we connected. I uh, I can sorta hear your thoughts sometimes." the redhead confessed.

"I know. I can sorta see your thoughts sometimes. It's, I wanna say weird? But honestly, it was the highlight of my day a lot of the time. Even though I knew you were in pain, I still felt connected to you. I think we left some of ourselves in each other. And I'm a bit scared what it would mean if we have to be apart any time." Marcy replied, still gazing into her eyes and more serious than Bonnie had ever seen her before.

"Then stay." Bonnie breathed. "I think we could definitely overthink this, let's not do that. But this, you and me, it feels good and I want you to stay. Why not just come to bed and warm up a little and we'll look at apartments tomorrow morning after breakfast? The lease is up on this place soon anyway and I'm not gonna just abandon that little bit of myself in your head, I've gotta keep it close by to make sure you're looking after it. Besides if you went back to dating men now it might actually kill me."

"I'm still not sure if I'm all the way gay, you know. Not completely certain. But you know what? I'm definitely not straight. And I am really, _really_ gay for you." Marcy replied, unable to keep her face from spreading into a fierce kind of smile. It was an inexplicably liberating feeling to say it out loud, like she'd stepped around the curtain that had always been there and realised that what she'd thought had been her identity had actually been a part she was acting and her life was just the stage. Now she was walking through the audience and out into the real world, finally aware of who she'd always been underneath the act.

"Come to bed." Bonnie repeated, gently helping her unzip her sodden hoodie and jeans.

So that's what they did. They went to bed and snuggled, just held each other in deep relief at finally being reunited. Marcy wore a borrowed pair of pyjamas and was warm again, finally peaceful in a way she hadn't been in weeks, and Bonnie stoked the hair back from her face and breathed, 'I love you'. And when they woke the next day and had eventually finished kissing and exploring their unique connection to each other they went down to breakfast hand in hand, too busy smiling into each other's eyes to notice the bet money Finn reluctantly slid across the table to his grinning brother. They moved into their new apartment together a few weeks later and as Finn put it, were 'revoltingly in love'. Marcy always preferred to call it 'inseparable' and Bonnie silently agreed, through the mental link they shared.


End file.
